Virtualization generally refers to the concept of running one or more virtual machines that can share resources of a physical machine across various different environments. For example, in a virtualized system, different virtual machines can execute different operating systems and/or applications on the same physical machine, regardless of underlying hardware associated with the physical machine. One advantage that virtualization can provide is the ability to create a tuned virtual appliance that includes a fully configured application image with just enough operating system (JeOS) components and/or other components needed to run a particular application. For example, an independent software vendor (ISV) may develop virtual appliances to bundle one or more applications with an operating system into a virtual machine image that can be delivered to a customer, wherein the virtual machine image may include all of the information necessary to install and configure the application. Virtualization may therefore reduce or eliminate barriers associated with different computing environments, providing ISVs with increased flexibility for reaching new markets and customers.
As such, the concept of virtualization has important implications in simplifying the production and distribution of software by reducing or eliminating the need for hardware optimization. For example, an operating system vendor may simply create a virtual appliance that includes the components of the operating system (with or without other applications), where customers may then run the operating system within a hypervisor that emulates the relevant hardware environment. Furthermore, virtual appliances may be deployed in many different ways, including in hosted environments (e.g., to deliver an application as a service), cloud computing environments (e.g., to reduce the resources needed to run an application), or various other environments. Thus, virtualization provides important advantages for ISVs that may lack particular expertise for different computing environments, as virtual appliances may provide contained systems that have been thoroughly tested and configured for a particular application. Virtual appliances may also simplify issues relating to support, security, and complexity of software products by reducing the volume of operating system components, services, and applications necessary to deliver an application to customers that may have different computational requirements.
Despite the various advantages that virtualization can provide to software providers, existing virtualization systems tend to lack a simple yet repeatable process for creating virtual appliances. For example, virtualization has faced various barriers to adoption, including the perception that specific skills are needed to develop and support virtual appliances. That is, to create a virtual appliance, developers often have to possess knowledge regarding repositories where the relevant JeOS components or other software components may be available, as well as issues pertaining to dependencies or incompatibilities among software components. Moreover, a historic problem with open source software projects is that one developer may innovate or otherwise improve upon certain aspects of a project, yet the changes that the developer implements may not necessarily be made available to upstream distributions of the project. Alternatively, the changes may not become available upstream by the time other developers have begun to work on the same features or problems. As such, existing systems for developing virtual appliances tend to lack adequate mechanisms for simplifying the management of origin repositories and relationships between software components, and further tend to lack adequate mechanisms for sharing the work and knowledge of different virtual appliance developers.